In the case of a conching device known from DE-OS 39 34 047, the speed of the motor is adjusted in dependency upon a given motor current. By using this design, the maximum possible drive power during a conching process is to be maintained in accordance with the various states of aggregation of the chocolate mass. In FIG. 1 of the present application, the performance versus time during a conching process is illustrated graphically. In this connection, the illustrated plane beneath the curve represents the energy consumed, or work done for the conching process.
When using a conching device that can be operated both as a dry conching device and a liquid conching device by changing the speed and the direction of rotation of the rotors, a curve P.sub.1 will normally result, representing the current consumption and thus a parameter of the motor performance as a function of time. In this arrangement, the chocolate mass first assumes a dry-pasty condition during a time interval d1, whereupon it changes into a viscous-plastic condition during a desired time interval d2. About from an instant of time t3on, the chocolate mass changes into a liquid condition by the addition of fat and emulsifying agents, during which phase only a minimum of energy will be introduced. The liquid phase lasts for a time interval d3.
To shorten the conching time, it is also known to do the necessary conching work by increasing the transduction during the dry-pasty and viscous-plastic phase of the mass. The power curve P2 associated therewith is represented in FIG. 1 of the present application by P2. During a first time interval d4, the conching device operates at high speed, thereafter at a lower speed for a time interval d5. When the current intake of the driving motor is decreased due to the continuous softening of the chocolate mass, a higher speed will be employed during a time interval d6, and finally the conching process will be finished at a still high speed during a time interval d7, with the direction of rotation being reversed. Also when using a procedure as described in connection with the current curve P2, a dry-pasty phase results during a time interval d1, being followed by a viscous-plastic phase during a desired time interval d2.sub.2, and finally, after the admixture of fat and emulsifying agents at an instant of time t4, the chocolate mass will pass through a liquid condition during a time interval d3.sub.2. With this mode of operation, the time saving represented by s in FIG. 1 is accomplished due to the fact that the work performed in the case of current curve P1 from an instant of time t0 to t1 is equivalent to the work performed represented by a current curve P2 from an instant of time t0 to t2.
From the curve shape it becomes apparent that an area beneath an admissible maximum value M remains, as represented in diagonal hatching, which could be utilized to further intensify the conching work.
It is an object of the present invention to provide a method for operating a conching device, with which the time interval required for a conching process can be reduced by increasing the working capacity of the conching device. In addition, an apparatus for carrying out the method is to be provided.